1. Field of the Invention
The present invention relates to a golf club head and, more particularly, to a technique for improving the sound of an impact.
2. Description of the Related Art
In hollow golf club heads typified by a driver head, techniques for improving the sound of an impact by appropriately designing the hollow body construction have been proposed. For example, Japanese Patent Laid-Open Nos. 11-155982 and 2003-275345 disclose techniques for improving the impact sound by partially varying the thickness of a sole portion. Also, Japanese Patent Laid-Open Nos. 2002-186691 and 2003-102877 disclose techniques for improving the impact sound by providing a rib in a sole portion.
The volume of the typical hollow golf club head is increasing every year as its crown portion and sole portion are getting thinner, and their areas are increasing along with this trend. Thus, a low-pitched impact sound is more likely to be generated at the time of striking a golf ball. However, there are golfers who prefer high-pitched impact sounds and hence want golf club heads which generate higher-pitched impact sounds. Partially varying the thickness of a sole portion as disclosed in Japanese Patent Laid-Open Nos. 11-155982 and 2003-275345 produces the effect of increasing the pitch of the impact sound, but this technique has its limits. Also, providing a rib in a sole portion as disclosed in Japanese Patent Laid-Open Nos. 2002-186691 and 2003-102877 produces the effect of increasing the pitch of the impact sound, but this too has its limits.